14 
Magazine  of  the  School  of  Agriculture. 
and  therefore  indirectly  for  the  sustenance  of 
animal  life  on  our  planet. 
The  R.  A.  Society's  Journal  just  to  hand 
contains  news  of  still  more  interesting  dis- 
coveries. Dr.  Fream  therein  describes  the  ex- 
periments carried  on  by  Schlcesing  and  Laurent, 
which  it  is  needless  here  to  repeat  the  description 
of ; suffice  it  to  say  that  they  have  established 
the  following  conclusions  : — 
1.  That  the  leguminosns  (papilionneerej,  ns 
represented  by  peas,  are  able  to  draw  largely 
upon  the  free  nitrogen  of  the  air  for  pur- 
poses of  growth. 
2.  Some  of  the  inferior  green  plants  (e.g.,  mow*, 
alga)  possess  the  same  property . 
3.  In  the  conditions  under  which  the  ex- 
periments were  conducted,  bare  soils — that  is 
soils  devoid  of  any  apparent  vegetation — failed 
to  nitrogen  in  any  measurable  quantify. 
Oats,  mustard,  cress,  spurrey,  likewise  failed 
to  fix  the  free  nitrogen  under  conditions  iden- 
tical with  those  in  which  peas  fixed  it  abun- 
dantly. Dr.  Fream  concludes  that  the  growth 
and  decay  of  mosses  and  other  cryptograms 
must  enrich  our  soils  with  the  nitrogen  they 
acquire,  and  considers  that  the  stores  of  nitrogen 
which  our  cultivated  lands  contain  are  probably 
due  to  the  accumulated  remains  of  mosses  and 
other  rootless  plants. 
Whether  mosses  and  algae  possess  the  power 
of  direct  assimilation  of  free  nitrogen,  or  whether 
they  effect  a symbiosis  similar  to  that  which 
exists  between  papilionaceous  plants  and  the 
nodule  forming  microbes,  is  a problem  which 
still  awaits  investigation,  and  this  will  doubt- 
less be  forthcoming  in  due  course.  Meanwhile, 
the  results  of  the  experiments  briefly  noted  here 
are  of  the  greatest  interest,  and  serve  to  add 
another  link  to  the  chain  of  facts  which  are 
so  greatly  modifying  our  views  concerning  the 
nutrition  of  plants. 
A SUBSTITUTE  FOR  CATTLE  MANURE. 
Dear  Sir, — Cattle  manure  in  sufficient  quan- 
tities for  agricultural  purposes,  especially  for 
coconut  cultivation,  is  very  difficult  to  obtain. 
It  has  struck  me  that  we  should  therefore 
strive  to  manufacture  a compost  resembling- 
cattle  manure  as  nearly  as  possible.  Though 
the  “bulk”  of  cattle  manure  is  a drawback 
and  stands  in  the  way  of  its  easy  transport, 
yet  I think  I am  right  in  stating  that  its  chief 
manorial  value  is  its  bulk.  A large  quantity  of 
vegetable  matter  decaying  in  the  soil  favourably 
affects  the  mechanical  condition  of  both  stiff  and 
light  soils,  gives  out  gases  to  disintegrate  them 
and  absorbs  as  humus  the  ammonia  of  the  atmo- 
sphere. If  the  very  large  quantity  of  water  it 
contains  could  be  driven  off,  it  will  be  an  ad- 
vantage ; but  that  is  out  of  the  question. 
1 think  we  have  the  basis  for  a compost 
to  take  the  place  of  cattle  manure  in  fibre  dust. 
As  it  leaves  the  mills  it  is  as  full  of  water  as 
a sponge.  I think  a press  can  be  devised  to 
expel  it  at  a moderate  cost.  1 know  there 
are  many  who  believe  that  fibre  dust  has  no 
manurial  value.  I am  not  of  those.  But  even 
if  it  has  no  manurial  value,  it  is  useful  as  an 
absorbent  for  the  purpose  1 indicate.  Husks  are 
composed  of  over  75  per  cent  of  Potash,  and  it 
is  hard  to  believe  that  in  the  fibre  alone  is 
to  be  found  this  valuable  constituent. 
The  principal  constituents  ot  cattle  manure 
are  Nitrogen,  Potash,  Phosphoric  Acid  and  Lime. 
B ill  not  the  addition  of  these  to  fibre  dust,  with 
the  moisture  expelled  from  it,  give  ns  a manure  as 
valuable  as  cattle  manure  and  less  bulky  be- 
cause containing  less  watery  If  it  will,  the  next 
question  that  arises  is,  what  manures  we  must 
use  in  the  compost  to  supply  the  leading  consti- 
tuents of  cattle  manure.  For  Nitrogen  gas  liquor 
suggests  itself,  for  Phosphoric  Acid  and  Lime 
Bones,  and  for  Potash  ashes,  the  chief  objection  to 
Gas  Liquor  is  the  large  quantity  of  water  it  con- 
tains,and  this  is  a serious  objection  where  transport 
is  considered.  V\  e want  something  more  concen- 
trated, and  guano  has  suggested  itself  to  me. 
Owing  to  its  higly  stimulating  qualities  it  is  a 
manure  that  is  very  little  used  : but  with  a large 
quantity  of  fibre  dust  to  counteract  that,  I think 
the  most  cautious  will  not  hesitate  to  use  it. 
Guano  is  considered  the  richest  and  most  concen- 
trated of  manures,  and  will  therefore  he  the  best 
manure  for  a compost  to  be  composed  largely  of 
undecayed  vegetable  matter.  A good  guano, 
bought  on  a guaranteed  analysis,  will  be  able  to 
s up] j 1\  all  the  Phosphoric  Acid,  Nitrogen  and 
Lime  the  compost  will  want  to  'assimilate  it  in 
composi  ion  to  cattle  manure,  with  the  exception 
of  Potash,  which  ashes  will  lie  able  to  supply.  1 
suppose  the  compost  will  be  far  more  concentrated 
than  cattle  manure,  and  will  have  a higher  pro- 
portion of  its  leading  constituents. 
1 shall  thank  you,  Sir,  for  your  editorial  opinion 
on  the  suggestion  I have  made,  for  if  it  accords 
with  mine,  and  the  Fibre  Mills  can  see  their 
way  to  press  the  water  out  of  fibre  dust  when 
occasion  demands,  a valuable  manure  will  be 
within  the  reach  of  advanced  agriculturists  li  vino-, 
in  and  around  Colombo.  p, 
28th  July,  1892. 
[Received  too  late  for  notice  in  this  issue. — Ed.] 
-o. — 
GENERAL  ITEMS. 
Sa]\  s the  .timber  1 rades  fhoumctl  t — V." hero  trees 
naturally  send  their  fibrous  roots  to  a good 
depth  below  the  surface,  it  is  highly  probable 
that  the  practice  of  digging  about  the  trees  is 
beneficial,  but  it  is  certainly  opposed  to  common 
sense  to  suppose  that  the  annual  destruction  or 
mutilation  of  the  effective  feeding  roots  of  a tree 
should  promote  it.s  health  and  luxuriance.  On  the 
contrary  it  is  calculated  to  effect  serious  injury. 
The  advantages  claimed  for  the  practice  of  allow- 
ing the  surface  of  land  planted  with  trees,  to  be 
covered  over  with  grass,  are  that  the  soil  is 
permeated  by  them  and  through  the  operation  of 
earthworms,  and  is  thus  kept  aerated  and  sweet,  the 
fibrous  roots  of  the  trees  getting  every  opportunity 
of  ramifying  the.  earth,  The  grass  also  keeps  the 
roots  of  the  trees' shaded  and  cool. 
Musk-seeds  now  form  a regular  article  of  com- 
merce, and  are  quoted  among  other  products  in 
the  ordinary  trade-lists;  they  are  sometimes 
known  as  as  “ graines  d’Ambrette,”  and  are  the 
produce  of  Hibiscus  Abelmosckus,  a plant  grow- 
ing to  a height  of  from  two  to  four  feet,  be 
